3 * \file PreviewLoader.h
4 * This file is part of LyX, the document processor.
5 * Licence details can be found in the file COPYING.
7 * \author Angus Leeming
9 * Full author contact details are available in file CREDITS.
11 * graphics::PreviewLoader collects latex snippets together. Then, on a
12 * startLoading() call, these are dumped to file and processed, converting
13 * each snippet to a separate bitmap image file. Once a bitmap file is ready
14 * to be loaded back into LyX, the PreviewLoader emits a signal to inform
15 * the initiating process.
18 #ifndef PREVIEWLOADER_H
19 #define PREVIEWLOADER_H
21 #include "support/signals.h"
25 #include "ColorCode.h"
35 class PreviewLoader : public QObject {
38 /** We need buffer because we require the preamble to the
41 PreviewLoader(Buffer const & buffer);
45 /** Is there an image already associated with this snippet of LaTeX?
46 * If so, returns a pointer to it, else returns 0.
48 PreviewImage const * preview(std::string const & latex_snippet) const;
62 /// How far have we got in loading the image?
63 Status status(std::string const & latex_snippet) const;
65 /// Add a snippet of LaTeX to the queue for processing.
66 void add(std::string const & latex_snippet) const;
68 /// Remove this snippet of LaTeX from the PreviewLoader.
69 void remove(std::string const & latex_snippet) const;
71 /** We have accumulated several latex snippets with status "InQueue".
72 * Initiate their transformation into bitmap images.
74 void startLoading(bool wait = false) const;
76 /** Connect and you'll be informed when the bitmap image file
77 * has been created and is ready for loading through
78 * lyx::graphics::PreviewImage::image().
80 typedef signals2::signal<void(PreviewImage const &)> sig;
81 typedef sig::slot_type slot;
83 signals2::connection connect(slot const &) const;
85 /** When PreviewImage has finished loading the image file into memory,
86 * it tells the PreviewLoader to tell the outside world
88 void emitSignal(PreviewImage const &) const;
90 /// Which buffer owns this loader.
91 Buffer const & buffer() const;
92 /// The background color used
93 static ColorCode backgroundColor() { return Color_background; }
94 /// The foreground color used
95 static ColorCode foregroundColor() { return Color_preview; }
97 double displayPixelRatio() const ;
101 void refreshPreviews();
105 PreviewLoader(PreviewLoader const &);
106 void operator=(PreviewLoader const &);
108 /// Use the Pimpl idiom to hide the internals.
110 /// The pointer never changes although *pimpl_'s contents may.
114 } // namespace graphics
117 #endif // PREVIEWLOADER_H